The present invention relates to drive systems for automatic clothes washers, and more particularly to improvements in a clutch mechanism to be incorporated in a vertical axis washer having a planetary drive system.
Automatic washers having a direct drive system between the motor and agitator/wash basket require a clutch mechanism so that the washer will be able to selectively operate in a agitate mode, wherein the agitator is oscillated while the basket is held stationary, and in a water extraction or "spin" mode, wherein the agitator and basket are spun together. Conventional machines utilizing this drive system incorporate a spring clutch or a spline clutch with a solenoid to actuate the clutch, moving the clutch member vertically on the motor shaft to selectively engage or disengage a drive connection with the wash basket.
Spring clutch mechanisms use a wrap spring clutch, in which the torsional tension in a coil spring encircling a drive shaft is varied such that the coil spring selectively grips or idles on the shaft. In this matter, the motor drive shaft is coupled to the wash basket drive system. Wrap spring clutches are typically expensive due to the tolerances and process controls required for reliable operation.
Previously known spline clutch and solenoid mechanisms are usually complicated arrangements, requiring precisely machined mating surfaces and complicated actuation mechanisms. The complexity of such arrangements renders them relatively expensive and unreliable.
U.S. Pat. No. 4,969,341 issued to Burk et al. on Nov. 13, 1990, teaches a clutch mechanism in the drive system of an automatic washer. This clutch system is a spline and solenoid clutch mechanism similar to the clutch mechanism contemplated in this application. Burk describes a solenoid operated cam, clutch slider engagement means connected to the basket and a clutch plate engagement means connected to the motor. Engagement of the clutch slider with the clutch plate is controlled by the solenoid actuated cam. A resilient member urges the clutch slider into the clutch plate. The profile of the splines is a combination sawtooth and square tooth profile, but is such that during engagement of the clutch plate and clutch slide, collisions may occur between the splines of the clutch means and the complimenting groove of the other clutch means during steady state spin such that unacceptable rattling may occur. The object of the present invention is to provide a tooth profile which will eliminate rapid collisions between the splines and grooves of the clutch members which causes unacceptable rattling. It should be noted that U.S. Pat. No. 4,969,341, was issued less than one year prior to the filing date of the present application and is assigned to the same assignee as the present application.